refactor(SwingSet): Improve config documentation, typing, and async function implementations

[gibson042]

Description

• Document new config parameters (defaultReapGCKrefs and vat-level neverReap/reapGCKrefs, plus node-specific nodeOptions)
• Remove obsolete config parameters (vat-level name/metered/virtualObjectCacheSize)
• Improve the accuracy of SwingSet config types in both JSDoc and Patterns
• Simplify some async functions for better comprehensibility and interactive debugging (e.g., vats and bundles both require one of sourceSpec/bundleSpec/bundle, but the former additionally support creationOptions/parameters options while the latter do not)

Security Considerations

None known.

Scaling Considerations

n/a

Documentation Considerations

None in particular.

Testing Considerations

n/a

Upgrade Considerations

n/a